The Stereo display has become a major trend of the display field. The basic principle of the stereo display is to give the stereo perception by binocular parallax, i.e., provide a left eye with a left-eye image and a right eye with a right-eye image, and the two offset images are separately present to the left and right eye within the time of duration of vision, then, a stereoscopic image having a depth will be seen after the brain gets the two different images.
Currently, a parallax barrier approach 3D is the most popular 3D display technology, and its basic structure includes a display unit and a parallax barrier under the display unit. The parallax barrier is a grating having transmission stripes and shading stripes arranged alternately, wherein the width of the transmission region is in a range of 20-70 microns, and the width of the shading region is about from tens of microns to hundreds of microns.
A grating is usually made by using photolithography or inkjet printing technology. When the photolithography is used to make a grating, it has a high precision, but the process is very complex and the production efficiency is low. Theoretically, an inkjet printing technology can be used to make a grating, that is, the shading stripes of the grating are directly printed on a substrate. This method is simple and can improve the efficiency of making the grating. If the inkjet printing technology is used to make a grating, after one shading stripe is printed, the printhead is required to be controlled precisely to move to a center of a next shading stripe for next printing. Thus, it requires a displacement control apparatus with a small stepping to make the grating because the distance between two adjacent shading stripes in the grating is very small, while it is hard for a transmission in the conventional technology to reach such precision, and it is very expensive even there is such one. The inkjet printing approach is hard to be implemented.